An electromotive wheel device has been provided for the handicapped person to easily move in present devices, the motor and battery are implemented on the frame of a wheelchair, and the battery current is supplied to the switch of the motor. The wheel of the wheelchair is driven by the output shaft of motor. For some electromotive wheelchairs, before driving the wheel, the speed of the output shaft of the motor is reduced by a speed reducer. In the conventional electromotive wheelchair of the prior art, when the battery power is exhausted, the wheelchair is difficult to drive, even if the power of the output shaft of motor is directly transferred to the axle of the wheel or indirectly transferred to the axle through a speed reducer.
It is recognized by those skilled in the art that the motor shaft is driven by the variation of the induction electromagnetic force formed between the stator and the rotor. As the power of the motor is interrupted, although the motor is static, the attractive force of the permanent magnetic field between the stator and the rotor inside the motor prevents the relative rotation between the stator and the rotor, so it is very difficult to drive the output shaft of motor. Because the output shaft of the electromotive wheelchair is connected to the wheel axle of the motor, the latter is difficult to rotate if the former is difficult to rotate.
It is well known by those skilled in the art the speed reducer consists of an input shaft and at least an output shaft. It is labor-saving if the output axle is driven by the input axle, however, it is difficult to drive the input axle by the output axle. If the driven structure of the electromotive wheelchair by the motor is indirectly transmitted by the speed inducer, then driving the wheelchair with a static motor is exhausted, and is often occurred in the products of which the wheel axle is driven by the motor, for example, electromotive wheelchair, electromotive motorcycle, electromotive bicycle, electromobile or the like.
If the current of the wheel axle of an electromobile is interrupted and the motor is motionless, the axle must also rotate and not be inhibited by the magnetic force of the permanent magnet inside the stator and the rotor. But this ability is either unknown by those skilled in the art, or it has been discovered but not resolved.